Lifting device



M y 1949- I E. H. PETTLE'R 2,468,999

LIFTING DEvicE Filed 001;. 18, 1946 INVENTOR j Z 3/ BY ATTORNEY PatentedMay 3, 1949 IIIFTING DEVICE EugeneH-s vRettle1:;,Beazver; Ba;

Application October 18, 1946; SerialiN'o. 7.04; 1,03

2;.Glaiins; 1-.

This invention relates to" lift trucks ofthe type utilizing: a hoistingfork adapted for manipulation ofthe loa'd 'on the floor'a-nd forstacking or placement purposes.

It' is among the objects of theinvention to provide an improved formoflifting' fork which shall lie-capable of engagingg lifting andstacking or placing loads'=oonsisting-"of a;- plurality of units, suchas brick; containersand'--' the like, without any-bottom" supports;

further object of the invention is the provision of* a lifting hoistemployinga plurality of gripping devices operable from a; common source,includingmeans-forlocking the gripping elements to the=load by theirownpressure.-

A\ furtiien object of the invention is the provision of a speciallifting' device consisting of a pluralityofspaceet for-k members havingreinforcing means constituting. pressure abutments which shall be"movably' mounted to facilitate placement. of.- the lifting. device;around? the? load to be handled.

These and other objects. of the. invention will become more'apparentftom a consideration of the accompanying drawing;.constituting: as parthereon, in whichlike reference; characters. d'esi'gnate likapartsandinwhichi Figs; 1? and 2 aretop plaman'diside elevational views,vrespectively, of a lifting; truck; utilizing hoist mechanism embodyingthe principles of this invention;

Fig. 3 a side elevational view of a hoist;

Fig. 4 a front elevational view thereof, illustrating its positionrelative to a load to be lifted;

Fig. 5 a top plan view of the hoist; and

Fig. 6 a cross sectional view of one form of a pneumatic type ofgripping element.

In the drawing the numeral 1 designates a lift truck of a conventionaldesign used in industrial plants for lifting articles in productionlines, the truck being no part of the present invention. In theparticular lift trucks to which the invention apper-tains. a hoist inthe shape of a elescoping frome member 2 is mounted on the front end ofthe truck, the particular shape of frame, or whether it be hydraulicallyor otherwise operated, being of no significance to the presentinvcntion.

The movable element of the hoist is a frame member 3, Fig. 5, on whichare mounted forks 4 that support and lift the load. These forks areusually in the shape of skids or sleds which may be placed under aloading platform on which the articles to be handled are loaded. Inaccordance with the present invention the forks are not placed beneaththe load but around the side of the load and are providedwithsideframesii'i of oliannel shape as-shown'in-Fig? 5'.- The forks areadjustable towidth by a splice bar t at; the rear having-- pinholes Tfor receiving a pin 8 whereby the*-for-kss may bespace'd for'load's ofdifferent width withintheli'mits of their' adjustment. A siinil'arbar s,having fiangedends iii, is disposed in the channel of the verticaluprights 5'. It is likewise a splice bar, as shown, having pin holes Mfor receiving the-anchorbolt' 12 sothat the front-bar 9' canbe adjustedtothe same width asthe-rear bar As shown in Figs. 3' and 4; the bar 9'is suspended by cables l3 extending over guide wheels M that are-Woundby'a= shaft lithat' ispreferably motor driven, there being twosuspension cablesas shown in Fig: 4 to-ba1ance therod 9 in.it's-vertical sliding movement inchannels 5-.

The fork element's fiareprovidedwith hydraulic jacks l6 connected to-a'source of pressure fluid at. I]; Figs; 3. and 4; there being four setsof jackssliown, although any desired number may heutili'zeddependingupon the character of the load t'oibe handled.

The forks-:4 are preferably I-' beams in which the jacks I6? are.mounted, and in theform of grippingsdeviceeshown imEig; 6 an inflatabletube I8 is employed in place=of-"tlie jacks- IS,- the tube running: the:full length ofit-h'e 1- beams and being connected to the pressure fluidsource I! to exert a gripping action on the load when inflated, suchtube being protected by the flanges of the I beam.

In the drawing, brick l9, such as fire clay brick, is illustrated as theload to be handled, there being four rows of brick seven brick high, asshown in Figs. 4 and 5. The improved form of lifting hoist may also beemployed for handling boxes in food factories or in industrial plantswhere the product is packaged for shipment.

The operation of the above described lifting hoist is briefly asfollows. The locking bar 9, Figs. 3 and 4, is raised from the positionshown in Fig. 3 where it is in substantial register with thelongitudinal axis of the forked members 4 o to the upper limit of itstravel which is at the top of the channels 5, the winch or motor drivenshaft l5 being actuated for that purpose. When it has reached the upperlimit of its travel in the channel frames 5, the forks 4 and side frames5 are separated by a space which may be termed the loading space thathas been previously determined by adjustment of the locking bar 9 andthe rear bar 6 to suit the width of the load to be handled.

In case of the brick l9, as shown in the drawings, the fork arms 4 havebeen adjusted to embrace rows of brick with sufficient clearance toclear the jacks 16 when the lifting truck is maneuvered to the positionof the pile. The truck is advanced to the position where the forks lhave been aligned with the stacked brick, as shown in Fig. 5, with thejacks IS in substantial center of each transverse row of brick. When inthis position the winch shaft [5 is operated in the reverse direction tolower the locking bar 9 to the position shown in Fig. 3, and pressurefluid through the source connection IT is then applied to the hydraulicjacks l6 which exert the necessary gripping pressure against the facesof the bottom row of the brick as shown in Fig. 4. The gripping pressureof the hydraulic jacks l6 reacts against the heads ID of the tie bar 9so that the I beam shaped forks 4 are rigidly secured against lateraldisplacement which would otherwise result from the pressure of thehydraulic jacks abutting against the faces of the brick.

When so engaged the load of brick is rigidly held and adapted to belifted as shown in Fig. 4 to any desired height within the limits oftravel of the telescoping frames 2. The truck then transports the loadto wherever it is desired, such as a truck bed for hauling or a stockpile for stacking. When the load has been brought to rest to its newposition, the hydraulic pressure of the jacks I6 is released and thefront tie bar 9 is again raised by the winch shaft I6 to its upperposition to clear the top of the load of brick, in which position thehoist truck is free to back away, leaving the load in place.

Where a flexible tube, such as the member l8 of Fig. 6 is employed inplace of the jacks I6, the application of pressure fluid eifects a firmgripping action of the forks with the load to be hoisted because theflexible tube l8 will lay itself on any surface with which it comes incontact.

The gripping fork type of hoist, as herein disclosed, may obviously beusefully employed in handling rectangular containers, such as boxes orpackages containing food products or the like, and may be utilized forlifting any objects having parallel fiat faces, either as single unitswhen of a large size, and in multiple units as in the case of the bricksherein illustrated.

Although one embodiment of the invention has 4 been herein illustratedand described, it will be evident to those skilled in the art thatvarious modifications may be made in the details of construction withoutdeparting from the principles herein set forth.

1' claim:

1. In a lifting hoist, a pair of gripping forks comprising a pluralityof substantially rectangular frames in parallel alignment, the frontuprights of which are channel members for receiving a tie rod that isslidable vertically therein, a tie rod disposed in said channels, theends of which are adapted to interact vnth said channel to preventdisplacement of the tie bar therein, means for raising and lowering saidtie bar, and means mounted on the lower horizontal frames of said forksfor exerting a gripping pressure on a load disposed between said forkswhereby the load is supported on said forks from pressure exerted on theside of the load.

2. A lifting device for truck hoists comprising a pair of I beams havingan adjustable spacer bar at the rear thereof to vary the space betweenthe I beams, gripping elements mounted on the inner channels of the Ibeams, a channel joined to the ends of said I beams and extendingvertically a distance in excess of the height of the load to be hoisted,a tie bar movably mounted in said channel members, hoist mechanism forraising and lowering said tie bar to clear the load when the I beams arebrought into parallel alignment with the side faces of the load and tosecure the I beams against lateral displacement when the gripping meansare actuated, and means for energizing said load gripping means tosimultaneously subject them to gripping force when brought intoengagement with the load.

EUGENE H. PETTLER.

REFERENCES CITED The following references are of record in the file oithis patent:

UNITED STATES PATENTS Number Name Date 2,213,629 Fontaine Sept. 3, 19402,308,648 De Vry et al Jan. 19, 1943 2,323,810 Fontaine July 6, 19432,403,356 Francis July 2, 1946

